Apparatus for the manufacture of sulphuric acid



I June 25, 1935. E; IQQTHAMMEL. 2,006,031

APPARATLIS FOR THE MANUFACTURE OF SULPHURI C ACID Filed April 5; 1929 2 Sheets-Sheet 1 3.8 &

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E. ROTHAMMEL 2,006,031

APPARATUS FOR THE MANUFACTURE OF SULPHURIC ACID Filed April 5, 1929 2 Sheets-Sheet 2 Patented June 25, 1935 UNITED STATES APPARATUS FOR THE MANUFACTURE OF SULPHURIC Acm Erich Rothammel, Pforzheim, Germany, assignor to the firm Sulfurit S. A., Basel, Switzerland Application April 5, 1929, Serial No. 352,844

Claims. ((31. 23-261) This invention relates to an apparatus for economically producing sulphuric acid of 60 B.-, a Glover apparatus being employed exclusively for producing sulphuric acid.

A Glover apparatus to-day generally serves exactly the same purpose as hitherto, namely to denitrate the nitrous acid flowing thereover and to vaporize the free water remaining in the acid, utilizing the heat contained in the hot gases, to concentrate the uncombined acid. A certain new production is thereby obtained in the uppermost zones shortly below the gas outlet, which amounts on an average to 16 to 18% of the daily production.

The intensive productional activity of the Glover tower according to the presentinvention has the result that the apparatus connected up with the Glover tower is not efiectedby non-uniform concentration of the roasting gases, as it receives gases which have been already used up as far as possible. The share of production of the Glover apparatus increases, according to the present invention, up to 60% of the total production of the system and in some instances beyond this. This also means that the subsequent apparatus can be considerably smaller than hitherto. If, for example, the usual lead chambers are added to the Glover tower, the chamber space can be reduced whilst retaining the same daily output. The output of the chambers themselves may also be increased per cubic meter of chamber volume. By adding suitable apparatus existing Gay-Lussac absorption chambers may be enlarged and therefore an increased output of the system obtained Without difiiculty, especially as according to the process of the present invention, this absorption apparatus is relieved.

By all these measures sulphuric acid absolutely denitrated is obtained the strength of which can be regulated in a simple manner within wide limits during the process without interruption, from the weakest to the strongest concentration of the Glover acid and if necessary even beyond same, all idle running of the individual apparatus being at the same time prevented by the measures taken.

An embodiment of the invention is illustrated by way of example in the two figures of the accompanying drawings.

A conduit 2 leading from the roasting plant leads to a denitrator 8 and thence through a nitrator 34 and a regulating device 3 to a nozzle 4 of the injector type, arranged on a suitable part of a Glover tower I, with which nozzle is connected an exhauster 9 with regulating device ii and pipe in terminating in the Glover discharge pipe l2, at the top of the Glover tower. A pipe 35 with regulating device 36 leads from the pressure line So of the exhauster 9 to the inlet. of the gas conduit 2 into the denitrator 8. "'6

The Glover discharge pipe i2 leads to a chamber ll, the lower end of which is connected by a conduit 12 to the'top of a chamber 13, which latter is similarly connected by a conduit 14 to a chamber 15, which latter is connected by a conduit 16 to a preliminary absorber ll, communicating through an exhauster 18 with a Gay-Lussac apparatus 19 discharging into the open through a conduit 88.

A conduit 63 with control element 64 leads from the high vessel 28 to the nitrator 34 and a conduit 58 branching from the conduit 63 and having a regulating device 60 leads to the denitrator 8. Aconduit 31 connects the nitrator 34 with a cooling device 24, a low level supply vessel 88, and a pump 20, the riser pipe 26 of which returns to the high vessel 29 and branches off through the conduit 6 to the Glover high vessel 38, from which the conduit 6| leads to the Glover tower l.

In Fig. 1, conduit 51 with regulating device 58 extends from the high vessel 50 to the denitrator 8, the discharge of which passes through the conduit 22 to cooler .43, and from there, on the one hand, to vessel 68 by way of a conduit provided with a regulator 23, and from vessel 68 to the pump on the other hand, to low level supply vessel 45,'by way of conduit 39 with regulator '40, and from the vessel 45 to a. pump 41, the riser pipe 48 of which with regulator 49 leads back to the high vessel 50. Conduit 5| containing regulator 52 leads to acid storage vessels.

In Fig. 2 is shown a modification of the acid ilow from denltrator 8. Acid from denitrator 8 ilows' through conduit 22 and in part passes through the branch of conduit 22, provided with [a regulator 23, to cooler 24 and from the latter acid flows to vessel 68 and pump 20. The other part of the acid flowing in conduit 22 passes to cooler 43, flows through conduit 39, provided with regulator, to low level supply vessel 45 and. from there to a pump 41.

The Glover liquid discharge conduit leads through the cooling device 33, a low level vessel IT to a pump 21, the riser pipe l3 of which leads on the one hand to the Gay-Lussac high vessel 46 and on the other hand through the conduit 1 back to the Glover high vessel 30. 55

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through the injector nozzle 4.

till, the riser pipe 32 of which leads back to the high vessel 29.

A pump 82 is connected to the vessei al; the riser pipe 83 of this pump terminating in'the pressure vessel 84, the discharge conduit 85 with the spraying elements 36 leading to the chambers l'l and i3, which in turn are connected to the low vessel 86 through the'discharge con duits 31 and 88 and cooling device 89, a regulator 12 being provided in the conduit 81. A conduit with regulator 9! leads back'to' the low vessel I! from the conduit 81.

A pump 34 is connected to the vessel 93, the riser pipe $5 of this pump terminating in the pressure vessel 96, the discharge'conduit- 9'! of which with the spraying elements '98 leads'to the chamber i5. This chamber is connected to the low vessel 93 through the conduit 99 with regulator M2. The conduit I00 with regulator 'iDi leads back to the low vessel 8!, whereas the riser pipe 85 is connected to the Glover high vessel til through the conduit 44. A suitable spraying nozzle of any known type may be employed for spraying acid into the Glover tower.

The operation is as follows:

The roaster gases arriving in the conduit 2 first pass through the denitrator 8, in which the acid fed from the high vessel 50 through the conduit 57 is subjected to the action of the roaster gases still containing their full percentage of S02 and is thereby denitrated, giving up its nitrous oxides to the gas current passing through and thereby continuously slightly prenitrating the gases. The denitrated acid is forced out through the conduit 5|.

The prenitrated gases passto the nitrator 34, which is sprayed with the whole of the high nitrous acid coming from the Gay-Lussac appara- The nitrogen oxides are for the greater part driven out by the sulphurous acid, and pass entirely into the gas current passing through,

which is nitrated to the strongest'possible degree. On leaving the nitrator the roasting gases are therefore charged with the greatest possible zle 4. I

Of the waste gases oversaturated with-nitroigen oxides, passing 01f from the Glover tower [to the chambers, a portion is drawn ofi by the exhauster 9 through conduit Ill and regulator ii and again forced into the Glover tower In' the nozzle the pressure exerts a suction which prevails in the nitrator 34 in the conduit 2, and back to the roasting furnace, so that the roasting process is influenced in a most favorable manner.

The gases injected into the Glover tower l turbulently mix with the gases arriving from the conduit 2 so that an extremely intensive new formation of sulphuric acid begins even in the lowermost zones of the Glover tower. The

fsprayed and flowing off acid remains almost free of nitrogen oxides in spite of the presence of these nitrous oxides because the gases at this point still 'ess.

contain a high percentage of S02 and effectively prevent any appreciable absorption. The remaining pressure of the exhauster 9, exerts a conveying action upon the gas mixture exclusively in the sense of the proper draught through the Glover tower to the next apparatus. The suction and pressure effect can be adjusted by the regulator I I.

The acid flowing off from the nitrator 34, which is still slightly nitrous, collects in the low vessel -68 and is forced back by the pump 2i? through the conduit 26 partly into the high vessel 29 and partly into the Glover high vessel 30. The Glover discharge acid, which is practically free from nitrous compounds, collects in the low vessel IT and is forced by the pump 2i partly to the Gay-Lussac high vessel 46 through the conduit I3 and partly back to the Glover high vessel 30 through the conduit 7. The partial returning of the discharge acid from the nitrator 34 and Glover tower i into their initial vessels 29 and 30 is intended merely to have suitable quantities of cooling acid always available for leading oif the large quantites of heat prevailing in this apparatus'. A suitable portion of the daily production of the Glover discharge acid practically free from nitrogen is fed through the conduit 65 into the vessel 45 and therefore into the internal circulation of the denitrator in order to there receive its final treatment and final denitration.

After denitration of the daily production the denitrator 8, can, if necessary, be connected up with the production process for the rest of the day. It then receives the Gay-Lussac acid with 'high nitrogen content from the high vessel 25 through the conduit 59, which acid gives up its nitrogen oxides to the washing gases passing through the denitrator 3, and thereby strongly nitrates these gases. For intensifying and accelerating the nitration, Glover discharge gases with a high percentage of nitrogen oxides may be injected into'the denitrator 8 through the extension conduit 35 with regulator 36 by the exhauster 9 in analogous manner to that used in the case of the Glover tower i. If desired the entire quantities drawn off may be led through the denitrator 8 in order to there effect the strongest nitration even at the commencement of the proc- The fresh nitric acid etc., added to the system, is preferably passed through the nitrator '34, so that it also becomes fully effective as early as possible in the process.

Therefore by means of the new process strongly or weakly prenitrated gases are supplied, and the nitrator 34 itself further continually nitrates the 'roaster gases most intensely, so that the Glover tower receives roaster gases nitrated to the highest degree even in its lowermost admission zone.

To these are added the quantities of nitrous substances drawn off and maintained in continuous circulation by the exhauster 9. The Gay-Lussac apparatus is permanently relieved by these last quantities, which are never withdrawn from the actual sulphuric acid production process, as they need never be absorbed. Accordingly the entire quantity of nitrous substances circulating in the system can be chosen correspondingly larger than usual, the Gay-Lussac apparatus being nevertheless not more heavily loaded, whereas increased reactions occur in the production apparatus.

The acid flowing into the Glover is preferably maintained at only about 57 to 58 B., as the sulphuric acid formation in the Glover increases the strength of the acid to the discharge strength of at least 60 B. The gases flowing .of! are oversaturated with nitrogen oxideabut only contain. a small quantity of $02. The inflowing acid will consequently'absorb a certain quantity of nitrous oxides and return the same automatically into lower Glover tower zones,

where they again are given up to the gas current flowing through, the internal gas tension and therefore the reaction speed being considerably increased at these points.

This continuous, internal automatic alternating process will, on the one hand, considerably facilitate the fresh formation of sulphuric acid in these tower parts and, on the other hand, relieve the Gay-Lussac apparatus by the quantities of nitrogen oxides held back, which in turn are again introduced where the S02 content of the pressure of the pump 82 into the chambers H and 13 in a closed circulation, and therefore the entire chamber space is continually filled with a finely divided acid rain. The flue gases discharged from the Glover tower. l and not withdrawn by'the exhauster pipe l first pass through this fine continuous rain in chambers II and are .turbulently mixed continually by the falling acid drops. Thus, on the one hand, nitrous oxides are released at first from the acid (the S02 still present therefore exerting a denitrating eifect on the sprayed acid), which oxides, together with the excesses of nitrous oxides coming from the Glover .tower convert the remaining S02 quickly for the greatest part into H2804. through the continual mixing and gyrating of the gases. In the chamber 13 the S02 content of the gas mixture passing through already drops considerably, so that it is .no longer capable of preventing a strong absorption of the nitrous, oxides by the sprayed acid which is itself exactly the same as that of the preceding chamber 1 l The acid flowing off from the chamber'l3 will therefore have a larger nitrogen content, than that of the chamber H. As

the two acids again unite in the low vessel Bi and mix, an acid with nitrogen content results therewith, the nitrogen content of which can continuallyadjust itself and requires no external addition of nitrogen compounds. This is possible only because the Glover apparatus uses up the roaster gases to a very great extent and these consequently can no longer effect a dcnitration of theacid flowing through the chamber "H.

,In order to convert the remaining $02 in the gases into H2804 on leaving the chambern, the chamber 15 is also sprayed with a thin very diluted acid of about 40 B. in a closed circulation entirely separate from the previous circulation.

The gas mixture entering the chamber 15 has a high excess of nitrogen oxides and oxygen, to which is added an excess of water in the shape of most flnely sprayed highly diluted acid. Through ways adjust the quantity accurately by the regulators It'll-402. Thus the production in the chamber 15 in the form of 40 acid passes into the circulation of the chambers H to l3, where it is concentrated for the first timeto 58 to 60 B. The quantities produced here are fed to the Glover-Gay Lussac circulation through the conduit 90 and there receive their flnal treatment followed by their denitration.

fiThe apparatus connected up behind the Glover tower may also be different from that above described, and for example consist of towers etc. Its manner. of operation depends entirely upon the principles above set forth.

If the capacity of an existing sulphuric acid producing plant is to be considerably enlarged .by introducing the process, the Gay-Lussac apparatus must also be extended either by adding a further Gay-Lussac'tower or, as shown in the drawings, by building in a preabsorber ll of any suitable construction, which in this instance would replace the Gay-Lussac I. The old Gay- Lu'ssac tower'lt'first receives the weakest nitrous acid from the high'vessel 46 which after passing through the tower 19 is led through the preabsorber 17, where it becomes fully saturated with nitrous oxides, i. e. in a similar manner to that usual .to-day when several Gay-Lussac towers are employed.

Fig. 2 of the drawings shows diagrammatically the same installation as shown in Fig. 1, except that in place of the absorber H, a Gay-Lussac tower 11a is substituted. The operation is the same as in Fig. 1. l i

I claim:

1. An apparatus for producing sulphuric acid by oxidizing SOs-containing gases by means of nitrogen oxides in the presence of water, comprising a denitrator, an inlet conduit for 502-601]- taining hot gases for said'denitratonat least one intake conduit for nitrous vitriol for said denitrator, at least one discharge conduit for denitrated vitriol from the said denitrator, a nitrator, a gas conveying conduit between the denitrator and the nitrator, at least one intake conduit for nitrous vitriol into' the nitrator, at least one discharge conduit for nitrous vitriol from the nitrator, a Glover tower, at least one intake conduit for nitrous vitriol to said Glover tower, a device for spraying the hot ascending gases therein with nitrous vitriol, a gas inlet conduit between the nitrator and the Glover tower, a regulating element in this conduit, a pressure conduit for the gases extending into the gas-inlet conduit and having an injector nozzle adapted to drawgases from the nitrator into the Glover tower at .the nozzle inlet to the latter, a connecting conduit'to subsequent treatment containers passing from the upper part of the Glover tower, a suction conduit from said connecting containers forthegases escaping from the Glover tower and not withdrawn by the suction conduit, at least one elevated and one low-lying supply ;vessel serving each treatment vessel in respect of the introduced'and discharged liquids, and a .Gay-Lussac tower for absorbing the remainder of the nitrogen oxides by means of nitrous vitriol. 2. An apparatus for producing sulphuric acid -,by oxidizing. SOs-containing gases by means of nitrogen oxides in the presence of water, comprising a denitrator, an inlet conduit for S02- containing hot gases to said denitrator, at least one intake conduit for nitrous vitriol to said denitrator, at least one discharge conduit for denitrated vitriol from the said denitrator, a nitrator, a gas conveying conduit between the denitrator and the nitrator, at least one intake conduit for nitrous vitriol into the nitrator and at least one discharge conduit for nitrous vitriol from the nitrator, a Glover tower, at least one intake conduit for nitrous vitriol to said Glover tower, a device for spraying the hot ascending gases therein with nitrous vitriol, a gas inlet conduit between the nitrator and the Glover tower, a regulating element in this conduit, a pressure conduit for the gases extending into the gas inlet conduit and having an injector nozzle adapted to draw gases from the nitrator into the Glover tower at the nozzle inlet to the latter, a-connecting conduit to subsequent-treatment containers passing from the upper part of the Glover tower, a suction conduit from said connecting conduit, a single exhauster connected to the said pressure conduit and also to the said suction conduit, a regulating element on the exhauster for the aspirated and forced gas currents, a. branch conduit proceeding from the said pressure conduit and extending into the gas conveying conduit before the denitrator, said branch pressure conduit exerting injector action at the inlet of the gas conveying conduit into the denitrator, the branch conduit being provided with a controlling element for the gas current which is forced therethrough, at least one discharge conduit for nitrous vitriol from said Glover tower, at least two subsequent-treatment containers for the gases escaping from the Glover tower and not withdrawn by the suction conduit, at least one elevated and one low-lying supply vessel serving each of the reaction vessels and containers in respect of introduced and discharged liquids, and a Gay-Lussac tower for absorbing the remainder of the nitrogen oxides by means of nitrous vitriol.

3. Device for making sulphuric acid from gases containing 302 and nitrogen oxides in the presence of water, comprising a denitrator, a nitrator, and a Glover tower having a draw-off conduit at its upper end, a supply conduit for S02- containing gases leading to the denitrator, gas conveying conduits between all three vessels for interinixing the gases to be reacted, means in the Glover tower for treating ascending gases with descending nitrous vitriol, a connecting conduit located outside of the Glover tower and comprising a suction conduit lea-ding from the draw-off conduit of said tower and a pressure conduit extending injector-wise through the connecting conduit between the nitrator and the Glover tower, a single exhauster between and connecting said suction and pressure conduits adapted to lead gases from the upper part of the Glover tower to the lower part thereof, an injector nozzle at the end of the pressure conduit, the eifective cross section of the suction conduit having a ratio of about 1:3 to that of the draw-01f conduit, chambers for the subsequent-treatment of that portion of the gas mixture which flows on in the draw-off conduit, said chambers being provided with devices for spraying ascending gas currents with descending nitrous vitriol, the first and second chambers being interconnected through at least one conduit, means in both chambers for returning the spraying liquid to the top thereof, conduits and containers for mixing the nitrous vitriol discharging from both chambers and again returning the mixture to the top of the chambers, a gasdischarge conduit extending from the last chamber, a preliminary absorber connected to said discharge conduit and provided with devices for spraying ascending currents of gas with nitrous vitriol,- discharge conduits for the spraying liquid from-the absorber, at least one Gay-Lussac tower connected to the preliminary absorber and having a spraying device for treating ascending gases with nitrous vitriol, a draw-ofi pipe for gases from said Gay-Lussac tower, and at least one discharge device for nitrous vitriol containing large amounts of nitrogen oxides leading from the Gay-Lussac 'tower.,

4. An apparatus for producing sulphuric acid by oxidizing SOs-containing gases by means of nitrogen oxides in the presence of water, comprising a denitrator, an inlet conduit for S02- containing hot gases for said denitrator, at least one intake conduit for nitrous vitriol for said denitrator, at least one discharge conduit for denitrated nitrous vitriol from the said denitrator, a nitrator, a gas conveying conduit between the denitrator and the nitrator, at least one intake conduit for nitrous vitriol into the nitrator, at least one discharge conduit for nitrous vitriol from the nitrator, a Glover tower, at least one intake conduit for nitrous vitriol to said Glover tower, a device for spraying the hot ascending gases therein with nitrous vitriol, a gas inlet conduit between the nitrator and the Glover tower, a regulating element in this conduit, a pressure conduitfor the gases extending into the gas inlet conduit and having an injector nozzle adapted to draw gases from the nitrator into the Glover tower at the nozzle inlet to the latter, a connecting conduit to subsequent-treatment containers passing from the upper part of the Glover tower, a suction conduit from said connecting conduit, a single exhauster connected to the said pressure conduit and also to the said suction conduit, a regulating element on the exhauster for the aspirated and forced gas currents, at least one discharge conduit for nitrous vitriol from said Glover tower, at least two subsequent-treatment containers for the gases escaping from the Glover tower and not Withdrawn by the suction conduit, at least one elevated and one low-lying supply vessel serving each of the reaction vessels and containers, in respect of the introduced and discharged liquids, and two Gay-Lussac towers adapted to absorb the remainder of the nitrogen oxides by means of nitrous vitriol.

5. An apparatus for producing sulphuric acid by oxidizing SOs-containing gases by means of nitrogen oxides in the presence of water, comprising a denitrator, an inlet conduit for the hot gases for said denitrator, at least one intake conduit for nitrous vitriol for said denitrator, at least one discharge conduit for denitrated nitrous vitriol from the said denitrator, a nitrator, a gas conveying conduit between the denitrator and the nitrator, at least one intake conduit for nitrous vitriol into the nitrator, at least one discharge conduit for nitrous vitriol from the nitrator, a Glover tower, at least one intake conduit for niitrous vitriol to said Glover tower, a device for spraying the hot ascending gases therein with nitrous vitriol, a gas inlet conduit between the nitrator and the Glover tower, a regulating element in this con-duit, a pressure conduit for the gases extending into the gas inlet conduit and having an injector nozzle adapted to draw gases from the nitrator into the Glover tower at the nozzle inlet to the latter, a connecting conduit to subsequent-treatment containers passing from the upper part of the Glover tower, a suction conduit from said connecting conduit, a single ex- 5 hauster connected to the said pressure conduit and also to the said suction conduit, a regulating element on the exhauster for the aspirated and forced gas currents, at least one discharge conduit for nitrous vitriol from said Glover tower, at least two subsequent-treatment containers for the gases escaping from the Glover tower and not withdrawn by the suction conduit, at least one elevated and one low-lying supply vessel serving each reaction vessel in respect of the introduced and discharged liquids, a preliminary absorber connected to the last subsequent-treatment container for the gases coming from the Glover tower and adapted to'absorb a portion of the nitrogen oxides contained in the gases coming from the Glover tower by means of nitrous vitriol, and connected thereto a final absorber of the Gay- Lussac type for freeing the gases from the last remainders of nitrogen oxides and yielding a nitrous vitriol which is saturated with nitrogen oxides.

ERICI-I ROTHAMMEL. 

